Lead-base alloy



UNITED STATES GEORGE H. WOBRALL, OF KIRKWOOD, MISSOURI, ASSIGNOR TOUNITED LEAD COM- PATENT OFFICE.

PANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

LEAD-BASE ALLOY.

No Drawing. Application filed August 11, 1919,

T 0 all whom it may concern:

Be it known that I, GEORGE H. WORRALL, United States citizen, residingat Kirkwood, Missouri, have invented the followin -describedImprovements in Lead Base Al oys.

My invention consists in a hard lead alloy suitable for machine bearingsand like purposes and containing lead, one of alkaline metals,-sodium orpotassiumyand mercury, with or without other ingredients. I havediscovered that mercury exercises a hardening effect upon lead alloyedwith either of these lead-hardening metals and can be used for thispurpose with economy and general improvement in the characteristics ofthe re sulting alloy.

1 My new alloy is made substantially as folows:

To a quantity of molten lead there is added in any suitable manner anamount of either sodium or potassium constituting less than 3% of theproduct. This alloy if allowed to cool will be found to possess acertain degree of hardness according to the known effect of sodium, orpotassium, on lead. To this mixture I add either in. the same vessel orelsewhere a small percentage of mercury approximating 1} and generallynot over 3%, and then cast the alloy into ingots ready for sale. Theaddition of mercury raises the hardness of the alloy and improves thefluidity when it is molten. By way of example an alloy containingpotassium 2%, the balance being lead, has a hardness approximating 18 onthe Brinell scale. The addition to such alloy of .5% mercury increasesthe hardness to above 20 on the same scale thereby enabling an in-Specification of Letters Patent. Patented Nov. 30, 1920.

Serial No. 316,607. Renewed May 28, 1920. Serial No. 385,083.

creased hardness to be attained with a minimum amount of potassium, andat less expense. Variation in the amount of mercury producescorresponding Variation in the resulting hardness. The outside limits ofthe ingredients may be stated as over 90% lead, less than 3% sodium orpotassium, and less than mercury, these proportions being subject tovariation according to the effects desired. I prefer to use less than 1%potassium and less than 1% mercury. Other metals, such as alulnlnum, tinor z nc may be added when desired to give certain additional effects to.the product, aluminum being useful for this purpose to prevent drossingof the product when molten, and when aluminum is introduced it isgenerally added in very small amounts less than 1% of the whole alloy,although still larger quantities of this or other metals can be addedwhen it is desired to produce an alloy of less specific gravity or ofdifferent appearance, the essential feature of this in vention being'the presence of a small GEORGE H. WORRALL.

